<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <!-- 选择下拉列表的颜⾊后，点击按钮删除选中的列表颜⾊。如下部分 html ```  ``` 
    比如当前选中的是 Black 那么点击按钮就把 Black 删除  -->
</head>
<body>
  <select id="text">
    <option>Red</option>
    <option>Green</option>
    <option>White</option>
    <option>Black</option>
  </select>
  <button onclick="del()">点击删除</button>
  <script>
    function del(){
      var sel = document.getElementById('text');
      var index = sel.selectedIndex;
      sel.options.remove(index);
    }
  </script>
</body>
</html>